$\mu$-$\tau$ reflection symmetry and radiative corrections

Abstract

The $\mu$-$\tau$ reflection symmetry is compatible with current neutrino oscillation data and easily realized under family symmetries. We prove that this symmetry preserves $\theta_{23}=45^\circ$, $\delta=\pm90^\circ$, $\rho,\sigma=0,90^\circ$, and can be embedded into the seesaw mechanism. The $\mu$-$\tau$ reflection symmetry preserved at a high energy scale $\Lambda_\text{FS}$ will be broken by radiative corrections and result in deviations of $\theta_{23}$ from $45^\circ$ and $\delta$ from $\pm90^\circ$ at the electroweak scale. We develop an analytical method to derive the corrections to all the mixing parameters. We perform a numerical analysis in the MSSM for $\delta=-90^\circ$ at $\Lambda_\text{FS}$, and observe that $\theta_{23}>45^\circ$ in the normal mass ordering, $\theta_{23}<45^\circ$ in the inverted mass ordering, and the sizable correction to $\delta$ prefers a negative sign. These deviations have definite directions and can be tested in the future neutrino oscillation experiments.